1. Field of the Invention
The present invention relates to a method for fabricating a semiconductor device, and more particularly, to a plasma spray apparatus and a method for fabricating a semiconductor device using the plasma spray apparatus.
2. Description of the Background Art
A plasma spray coating refers to a technique that a metal or a ceramic material is melted by a high temperature plasma which is generated by an intense current passing through gas, which is sprayed on a substrate to form a strong coating film on the substrate. This technique is well known in the field of architecture and mechanic painting field as well as the semiconductor device fabrication field.
FIG. 1 illustrates a generally adopted plasma spray coating apparatus in accordance with a conventional art.
With reference to FIG. 1, a cathode bar in the shape of pintle of a hinge is fixed by an insulator 2, and a hollow tube shape anode tube 3 surrounds the cathode bar 1. The anode tube 3 is also fixed by the insulator 2 at one end portion thereof.
The anode tube includes a tube 3a having a larger diameter and a tube 3b having a relatively smaller diameter which are connected to each other, and the cathode bar 1 is positioned in the larger-diameter tube 3a. 
The acute tip portion 1a of the cathode bar 1 is positioned near the end of one side of the smaller-diameter tube 3b. The smaller-diameter tube 3b serves as an anode for generating plasma and as a passageway for discharging the generated plasma, that is, a nozzle 3b. 
A gas injection port 4 of gas for formation of plasma is formed at the anode tube 3 in the vicinity of the tip of the other side of the cathode bar 1, through which plasma forming gas (inert gas such as Helium or Argon) is injected.
The other tip 1b of the cathode bar 1 is connected to a cathode terminal of a power source 7 by a conductor 6, and an anode terminal of the power source 7 is connected with the anode nozzle 3b through an excitation power source 9 by a conductor 8.
When the DC voltage coming from a power source 7 is applied between the anode and the cathode, to which a high frequency voltage is overlapped by the high frequency excitation power source 9, and thus, plasma gas (mostly, inert gas such as Ar is used for plasma gas) flows into the anode nozzle 3b in the direction of arrow (10), an electric arc 11 is generated between the front end 1a of the cathode bar 1 and the inner wall face of the anode nozzle 3b. 
In this case, the short electric arc 11 have an impact on the wall face of the anode nozzle 3b. Accordingly, a large amount of plasma gas 5 is supplied so that the generated electric arc goes out as far as possible in the anode nozzle 3b to form an anode point 12 far distanced from the cathode bar 1.
The plasma gas 5 flowing into the anode nozzle 3b is heated at a high temperature by the arc 11, broken to be changed to a plasma state and sprayed from the front end portion of the anode nozzle 3b. At this time, a spray coating material 15 is supplied thereto from a coating material injection pipe 14.
As indicated by an arrow 16 of FIG. 1, the coating material is mixed with the high temperature plasma 13 to instantly form a melting material. The melting material collides with the substrate 22 and a coating film 21 is formed on the surface of the substrate 22.
According to circumstances, the spray coating material 15 coming out of the coating material injection pipe 14 may be injected at the very front portion 17 of the opening of the anode nozzle 2 or may be injected at the very back portion 18 as indicated by arrow.
The above described plasma spray apparatus has been employed to form the coating film on the exterior of a stuff.
The present invention, however, adopts such plasma spray coating apparatus to fabrication of a semiconductor device.
In this respect, however, the following problems arise to adopt the conventional plasma spray apparatus as it is to fabrication of a semiconductor device.
First, if a thin film (a coating layer) is formed on the surface of a large scale semiconductor substrate by using a single plasma nozzle channel, the thickness of the thin film formed on the area close to the opening of the anode nozzle and the thickness of the thin film formed on the area distant from the opening of the anode nozzle become different. That is, it is difficult to form a uniform thickness of thin film on the large area.
Secondly, since the coating material itself coming out of the coating material injection pipe is not activated, an electric arc should be intense, to which, thus, a high DC voltage should be supplied from a power source. Therefore, a unit cost of process is increased.
Thirdly, as the semiconductor device is more highly integrated and have more functions, a necessity is growing that the substrate is heated for a very short time with a high temperature-rising rate.
In order to rise the temperature of the semiconductor device, there have proposed a method in which a plurality of halogen lamps are put close to the semiconductor device and a method in which a heater is installed at the lower portion of a suscepter supporting the semiconductor device.
These methods, however, are disadvantageous. First, as for the method for heating the substrate rapidly, due to the attribute of the Halogen lamp, it is not possible to increase the temperature-rising rate with a RTP (rapid Thermal Process) which rapidly heats the substrate by putting a plurality of Halogen lamps close to the semiconductor substrate. Also, the temperature-rising rate is hardly controlled freely. Meanwhile, In case of installation of the heater for the suscepter, since the suscepter, the medium, exists between the semiconductor substrate and the heater, it is not easy to increase the semiconductor substrate rapidly.
Therefore, an object of the present invention is to provide an apparatus for fabricating a semiconductor device that is capable of forming a thin film of an even thickness on a large substrate by using a plasma spray function.
Another object of the present invention is to provide an apparatus for fabricating a semiconductor device that is capable of rising the temperature of a semiconductor device rapidly at a even temperature by using a plasma spray function.
Still another object of the present invention is to provide a chemical vapor deposition method and a rapid thermal processing method for a method for fabricating a semiconductor device using the plasma spray apparatus.
To achieve these and other advantages in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided to an apparatus for fabricating a semiconductor device including: a plasma torch having a hollow convey tube of which one end portion is made of a conductor so as to serve as an inner electrode, for injecting plasma generating gas through one end portion, conveying and spraying a plasma frame through the other end portion; an energy applying unit for applying a microwave to the gas conveyed through the convey tube and adds an energy thereto; an outer electrode for surrounding the other end portion of the convey tube and its extended portion coaxially; an insulation tube positioned between the convey tube and the outer electrode for electrically insulating the other end portion of the convey tube and the outer electrode and surrounding partially the convey tube coaxially; a power source for applying a voltage to the inner electrode and the outer electrode; a suscepter installed facing the plasma frame sprayed from the plasma torch; a suscepter moving unit for moving the suscepter in the vertical and horizontal directions to the other end portion of the convey tube; and a reactive chamber for surrounding the other end portion of the convey tube and the suscepter and defining a reactive space.
In the apparatus for fabricating a semiconductor device of the present invention, the insulator tube is preferably a quartz tube.
In the apparatus for fabricating a semiconductor device of the present invention, the energy applying unit includes a waveguide resonator surrounding partially the convey tube in a closed type, and a magnetron for applying microwave into the waveguide resonator to excite the plasma generating gas conveyed through the convey tube.
The apparatus for fabricating a semiconductor device of the present invention further includes a reactive gas supply unit for supplying a reactive gas into the reactive chamber to form a thin film on the surface of the semiconductor substrate disposed on the upper surface of the suscepter by a chemical vapor deposition. In this case, the reactive gas supply unit is preferably installed to be positioned in the vicinity of the other end portions of the convey tube.
The apparatus for fabricating a semiconductor device of the present invention further includes a heating unit inside the suscepter.
In the apparatus for fabricating a semiconductor device of the present invention, a main convey tube may be commonly connected with one end portions of the convey tubes so that the plasma generating gas can be conveyed through the main convey tube into the convey tubes.
In the apparatus for fabricating a semiconductor device of the present invention, the energy applying unit may be installed in the main convey tube.
A semiconductor device fabricating process such as a rapid thermal process for heating rapidly a semiconductor device or a chemical vapor deposition process accompanying the rapid thermal process can be perform by using the apparatus for fabricating a semiconductor of the present invention.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.